I just did a plug presentaion on very simple system for doing this. It will take you just a few hours to set up but requiers on server to host the primary database and manual failover to the secondary DB. Again, it seems scary but from what I understand of your desire it is easy. However to get more indepth I need to know what you are hosting (Java, PHP, ColdFusion, etc) and what tech are you using to run it (Apahce/Tomcat, JBoss, Resin, GlasFish, etc.) and what databse you are connecting to (MySQL, DB2, Oracle, etc.) Not to mention questions on how your app handles session loss. On Wed, May 19, 2010 at 2:07 PM, keith smith wrote: > > > Currently we have two servers in our main data center. One serves our > shopping cart. The other contains quite a bit of content that is data > driven (reads). The content site is very active. The orders on the > shopping cart are spread apart by one or two minutes during the busiest part > of the day. We store a lot of data with each order so most of this is > writing. The shopping cart is backed up to the server in the other data > center. Supposedly if there is a problem, a few things need to be done to > the backup server in preparation to make it live, and a change to the DNS > and we are off and running. > > The problem I am trying to solve is the other server (content site) is not > currently backed up automatically. > > Another layer of this is these are managed servers. We have an excellent > relationship with the data center owner and have 24/7 access to him and his > staff. He manages all three servers and has always done a good job. > > I am the one tasked with keeping our sites online 24/7. > > I was hoping by configuring two servers, each in a different location, > that, in the event of one of the data centers being completely severed from > the Internet that the other server would automatically, without any human > intervention, take over the full load of the other server and those visiting > either of our sites would not know there had been an issue. > > In a nutshell I am trying to create an automated backup that is a automated > fail over solution. > > I appreciate all your feedback! > > ------------------------ > Keith Smith > > --- On *Wed, 5/19/10, Dan Dubovik * wrote: > > > From: Dan Dubovik > Subject: Re: load balanced configuration > To: "Main PLUG discussion list" > Date: Wednesday, May 19, 2010, 1:45 PM > > > The question I have, are you trying to actually load balance things? Or > just have a remote location that you can fire up with live data at a moments > notice? Basically, are you wanting an active/active configuration, or > active/passive? > > active/active across DC's can get kind of hairy depending on what the > network looks like. active/passive won't give you any performance gains, > but can simplify the configuration, while providing the HA you seem to be > after. As Kaia pointed out, what the traffic looks like (reads vs writes) > is a consideration. If it is something that users don't write to, and data > doesn't have to be replicated across DCs frequently, this further simplifies > things. > > Ultimately, the configuration will depend on what the application and > network looks like currently, and what level of redundancy you want / need. > > -- Dan. > > On Wed, May 19, 2010 at 1:40 PM, Matt Iavarone > > wrote: > >> I think the original question was around stateless load balancing, not >> clustering. Cross DC clustering is a headache, but HA web sites aren't >> exactly terchnical challenges these days. >> >> On May 19, 2010 4:33 PM, "Alex Dean" > >> wrote: >> >> >> On May 19, 2010, at 2:47 PM, keith smith wrote: >> >> > >> > >> > Hi Plug, >> > >> > I am considering combining the ... >> >> You're entering a world of pain. :) >> >> HA is cool, but is no panacea. If you haven't actually experienced >> downtime due to your server crashing or your datacenter losing connectivity, >> I recommend thinking long and hard about it. Don't solve a problem you >> don't have. The downtime created from unneeded failovers will likely exceed >> the actual/real downtime caused by either a server or datacenter being >> offline. Managing the cluster itself (as distinct from the services >> provided by the cluster) needs to be accounted for as an >> expense/responsibility. >> >> I don't want to sound overly pessimistic. I've set up quite a few HA >> clusters, and actually enjoy it most of the time. But it WILL cause you >> headaches in the middle of the night which you wouldn't have had if you only >> had a single server. >> >> Leave yourself lots of time to set up a development/test cluster, and >> abuse it in many ways. Pull out network cables, kill the switch, yank out >> power cables, etc. Do this with real hardware, not VMs. >> >> When the cluster nodes lose contact with each other, both will decide to >> become primary. This is a split brain. This can happen when the switch >> in-between them gets busy and starts dropping pings. Now, you can always >> recover from such things. I'm just recommending you become very familiar >> with these issues before going live with this setup. >> >> http://clusterlabs.org/wiki/Main_Page >> http://people.linbit.com/~florian/heartbeat-users-guide/ >> >> Let me/us know if you have specific questions once you start setting >> things up. Good luck! >> >> alex >> --------------------------------------------------- >> PLUG-discuss mailing list - PLUG-discuss@lists.plug.phoenix.az.us >> To subscribe, unsubscribe, or to change your mail settings: >> http://lists.PLUG.phoenix.az.us/mailman/listinfo/plug-discuss >> >> >> --------------------------------------------------- >> PLUG-discuss mailing list - PLUG-discuss@lists.plug.phoenix.az.us >> To subscribe, unsubscribe, or to change your mail settings: >> http://lists.PLUG.phoenix.az.us/mailman/listinfo/plug-discuss >> > > > -----Inline Attachment Follows----- > > > --------------------------------------------------- > PLUG-discuss mailing list - PLUG-discuss@lists.plug.phoenix.az.us > To subscribe, unsubscribe, or to change your mail settings: > http://lists.PLUG.phoenix.az.us/mailman/listinfo/plug-discuss > > > > --------------------------------------------------- > PLUG-discuss mailing list - PLUG-discuss@lists.plug.phoenix.az.us > To subscribe, unsubscribe, or to change your mail settings: > http://lists.PLUG.phoenix.az.us/mailman/listinfo/plug-discuss >